The present invention relates to a method of inspecting the surface of an object of measurement, such as a semiconductor wafer, and an apparatus for carrying out the method.
In a prior art method for inspecting the surface of a semiconductor wafer, a light beam from a light source is thrown on the surface of the wafer through an optical system, a scattered light beam reflected from the surface of the wafer is sensed by a photoelectric converting element through another optical system, the wafer and the optical systems, in the meantime, are given relative displacement to each other, a foreign matter on the surface of the wafer is inspected, and, when a foreign matter is detected, the position coordinates of the foreign matter are recorded.
However, when a foreign matter on the wafer surface is inspected, if there is a warp in the wafer, the position coordinates of the foreign matter in the planar directions, of the detected three-dimensional position coordinates of the foreign matter, are detected and recorded, deviated from the reference plane due to the warp in the wafer.